Question

the Jelly Junior High School color is made by mixing red paint with yellow paint . the ratio of red to yellow is 3 to 5 . how much red paint should be mixed with 20oz of yellow

Answer 1

To get the answer we can use proportion
3 red ----------------- 5 yellow
x red ----------------- 20 yellow
Crossmultiply now
3*20=5x            
60=5x        /:5    (divide both sides by 5)
60:5=5x:5
12=x - its the answer